Honda Motor Co will maintain the target for lease sales of its newest fuel-cell car after over a year since its launch despite the challenge of boosting productivity, the model's chief engineer said.

Honda's FCX Clarity, a sporty-looking fuel-cell sedan, is still a long way from mass production, the key to pushing prices lower, with a total of only 10 cars on the road in the United States and in Japan.

Honda, Japan's second-biggest auto maker, has said it is targeting lease sales of about 200 cars in the first three years in the two countries combined.

It aims to have the cars ready for sale in showrooms by 2015.

Fuel-cell vehicles are widely considered the ultimate longer-term alternative to today's conventional cars as they run on a clean and inexhaustible source of fuel, hydrogen, emit only water vapor and do not compromise driving performance.

Among automakers, Honda and its bigger rival Toyota Motor Corp were the world's first to put vehicles powered by fuel cells -- devices that produce electricity from hydrogen using a chemical reaction -- on the road in December 2002.

Still, the most difficult part is how to raise productivity, in particular for building the core part, fuel cells, as Honda is on the last and toughest part of the road toward commercialization, Sachito Fujimoto, FCX Clarity's chief project manager, said on Tuesday.

Everyday there's progress, Fujimoto said at the Reuters Global Climate and Alternative Energy Summit.

We would like to maintain the target (for 200 cars). It's my own dream to make fuel cell vehicles for the ordinary motorist. I would like to make the age of the fuel cell cars begin in earnest as early as possible, he said in an interview.

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(Reporting by Risa Maeda)